Will a Z10 STL100-1 be compatible for 4G service in future if any network provides in India?

I was planning to buy this Z10 STL100-1 keeping in mind that when any service provider will start to provide 4G service(which they currently don't), i'll be able to use it. But now i'm hearing a hell lot of things which says that STL100-1 won't support 4G! So, what do i do? Will STL100-2 or other work in India or i have no option but to buy a cellphone now and will have to change it when 4G service becomes active in this country? what do i do?

what if i don't know which band they will be using in future? because it's not yet introduced here. aren't there any specific standards about the band a particular country use? what do you recommend me to do? because i'm genuinely in love with this Z10! And i want my investment to pay off in future. Also, will this be the same case about Q5?

i just surfed a bit found out 1800Mhz and 2600Mhz(BSNL) and 2300Mhz(airtel) for India. So, STL100-2 contains these frequencies(1800Mhz and 2600MhzBSNL). so, it will be the choice if you belong to India in my opinion.

If you could share your links re: 1800 and 2600 MHz, I would appreciate it. No Z10 would work on the 2300 MHz (band 40) LTE network. No BB10 phone for that matter.

Also, if BSNL is truly going to be deploying LTE on 1800 and 2600 MHz, for the STL100-2 to work, they would have to be the FD-LTE bands 3 and 7. They certainly can't be TD-LTE, and maybe not some weird FD-LTE subset of 1800 or 2600 either (like band 9, which is band 3 subset.)

If you could share your links re: 1800 and 2600 MHz, I would appreciate it. No Z10 would work on the 2300 MHz (band 40) LTE network. No BB10 phone for that matter.

Also, if BSNL is truly going to be deploying LTE on 1800 and 2600 MHz, for the STL100-2 to work, they would have to be the FD-LTE bands 3 and 7. They certainly can't be TD-LTE, and maybe not some weird FD-LTE subset of 1800 or 2600 either (like band 9, which is band 3 subset.)

The BLSN, FD-LTE, 2300 band and what did you mean by 2600 subsets (and how they affect a BB10 phone)

Sure. FD(D) and TD(D) are two different types of LTE that are used by carriers in their network deployments (you can read about how they differ technically here, fourth and fifth paragraphs.) Typically, TD-LTE is used by carriers that have to make the most out of limited bandwidth. India is one of these countries where carriers have chosen to go with TD-LTE. Unfortunately, BB hasn't put out any phones that are TD-LTE capable--there have been plans/sightings, but no actual phones. So compatibility on band 40 (2300 MHz TD-LTE) can be ruled out right away.

As I'm sure you're aware, there are a lot of LTE bands. But what's "bad" is that relative to UMTS, a lot more of these LTE bands are actually in use worldwide. The OP says that BSNL (an Indian carrier) is deploying LTE in the 1800 and 2600 MHz ranges, but doesn't mention which bands. Bands are quite important when it comes to LTE, because a single range can host multiple bands (the 700 MHz range, for example, has at least four FD-LTE bands.) 1800 and 2600 have typically been deployed as FD-LTE bands 3 and 7, but Indian carriers have backed TD-LTE. So 2600 could be the 'usual' FDD band 7 (which, for example, Claro, Oi and TIM use in Brazil,) or it could be the TDD band 38 (which is what SKY Brasil uses.) So if BSNL deploys a b7 network--good news for Z10 -2 owners. But if they deploy a b38 network--no go with any BB10 phones.